Central does not wait for Zone Import threads to complete before shutting down

[Kiall Mac Innes]

Central does not wait for Zone Import threads to complete before shutting down.

See bug 1570859, and PatchSet #5 of https://review.openstack.org/300513 - where a fix was attempted but, swapped for a skip test.

[Kiall Mac Innes (kiall)]

Adding a tpool.killall() doesn't seem to have resolved the random CI failures caused by this, which is the only mechanism eventlet provides us to stop these threads. I'm not sure if it's really stopping them and the problem is more than just stopping the threads, or if eventlet isn't actually stopping them at all.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/316773
Committed: https://git.openstack.org/cgit/openstack/designate/commit/?id=96de5c139bcccf6cc6314bc9a8c579b996f2cb27
Submitter: Jenkins
Branch: master

commit 96de5c139bcccf6cc6314bc9a8c579b996f2cb27
Author: Kiall Mac Innes <email address hidden>
Date: Mon May 16 13:01:19 2016 +0100

    Skip zone import count test, reenable pool tests

    It looks like we may have found the cause of the CI failures, zone
    imports are stated during tests, but are not given time to complete.

    This (eventually) means they clash with other tests, causing the
    database is locked failures we've been seeing.

    Change-Id: I010a32affec54a8f12a4e7f5263a1d20a475d0dc
    Closes-Bug: 1570859
    Related-Bug: 1582241